If you’ve ever purchased a car, you know how many versions, styles, and colors are available for each manufacturer. Unsurprisingly, what’s under the hood is as versatile; while all the necessary components are, well, necessary to keep the vehicle running, they come in a wide variety of designs based on personal use and preference. From diesel fuel lift pumps to diesel filtration systems, you have the freedom to decide (within reason and space limitations) what goes in your car. This article will focus exclusively on fuel pumps.

Rotary Vane-Style Lift Pumps: Rotary vane pumps contain a paddle-wheel device within a larger circular housing. The wheel is offset within this housing, which creates a crescent-shaped cavity. The paddles slide in and out as the wheel spins, drawing fuel into the pump through the inlet; when the fuel reaches the narrow point of the crescent on the outlet side, it is compressed and pushed through the outlet. These fuel pumps are highly efficient, but they make a lot of noise.

Gerotor-Style Lift Pumps: Gerotor pumps are high-pressure, high-volume electric fuel pumps. By utilizing two gears (a spur gear and a ring gear) that work together to rotate the cavity, suction is created on the inlet and pressure is exerted on the outlet; this even balance is what makes Gerator pumps so efficient and able to build high pressures — and all without making any noise. However, they are susceptible to damage from contaminants and can experience cavitation because of the strength of the vacuum they produce.

Diaphragm-Style Fuel Pumps: Diaphragm pumps use a flexible membrane (usually a rubber composite) that moves up and down inside a chamber. The fuel only moves in one direction within that chamber. A lever on the pump fits into a lobe on the camshaft; as the cam spins, the lever is moved, pulling the diaphragm down and increasing the size of the pump chamber, which draws fuel into the pump. When the diaphragm pushes up (aided by a diaphragm spring), the fuel is forced from the chamber and into the feed line. Although they are more resistant to damage from contaminants and debris (like water, scale, rust, and dirt), their high vacuum makes diaphragm pumps vulnerable to vapor lock or cavitation. As a result, they’re usually recommended for carbureted applications where higher pressures aren’t needed.

Unless you are a qualified mechanic, we recommend consulting a professional before making any purchases or changes to your vehicle. Whether your car runs on a diesel fuel supply system or uses regular gasoline, you’ll be able to find a product that best suits your needs.